Method of connecting service lines to mains



Sept- 24, 1963 J. s. POWELL, JR 3,104,456

METHOD OF CONNECTING SERVICE LINES TO MAINS Filed June 27, 1960 2Sheets-Sheet l 55/ #is rra/eME/s.

,Mlm/s, .1f/ECW, .IQUSSELL He/QM Sept. 24, 1963 J. s. POWELL, JR3,104,456

METHODL oF CONNECTING SERVICE LINES To MAINS Filed June 27, 1960 2Sheets-Sheet 2 Ca/V4 r//AA/ 5.' pan/5u, Je,

United States Patent O METHD F CGNNECTNG SERVQE LHNES T li/APJS JonathanS. oweli, fir., 1231 Eroolrmere Road, Pasadena 2, Calif. Filed .lune 27,196i?, Ser. No. 38,922 2 (Ilaims. (Cl. 29-157) The present inventionrelates in general to amethod of and apparatus for making service lineconnections to gas mains, water mains, and the like, without serviceinterruptions to existing service line connections.

It will be understood that the term main is used herein to designate anyduid-conveying conduit, and the expression service line, as used herein,means any branch duid-conveying conduit connected to such main A generalobject of the invention is to provide an apparatus for and a method ofmaking service line connections which are respectively much simpler andmuch less time consuming, and thus far less expensive, than priorapparatuses and methods. Other general objects are to provide serviceline connections which avoid exposed underground threaded connections,which are easily protectible from corrosion, which avoid the necessityfor initially providing the mains with projecting fittings when themains are laid, thereby avoiding the possibility of having suchprojecting ttings broken ol by digging equipment, and the like.

More specically, a primary object of the invention is to provide aservice line connection and method which involve connecting a lateralstub conduit or nipple to the main or main conduit, and forming a holethrough the main to establish communication between the main and thenipple and, at the same time, preventing the escape of uid from the mainby isolating the portion of the main being Worked on from the atmosphereand by plugging the nipple with a lfusible plug. Subsequently, theservice connection is completed by connecting the service line to eitherthe main or the nipple. As a iinal step, the fusible plug in the nippleis heated, by the external application of heat, to melt out the fusibleplug, thereby establishing communication between the main and theservice line after the service connection has been completed, which isan important object of the invention.

Another object is to provide a service connection wherein the serviceline is either connected directly to the main around the nipple, or isconnected to the nipple itself.

A further object is to make all exposed connections between the serviceline and the main, or between the Serf vice line and the nipple andbetween the nipple and the main, bonded connections so that there are noexposed threaded connections. Such bonded connections may be weldedconnections in the event that the various components are made ofweldable metals, or they may be cemented connections in the case ofplastic components. Also, the bonded connections in question may be heatsealed connections with heat scalable plastic materials.

The foregoing objects, advantages, features and results of the presentinvention, together with various other objects, advantages, features andresults thereof which will be evident to those skilled in the art towhich the invention relates, may be achieved with the exemplaryembodiments of the invention described in detail hereinafter andillustrated in the accompanying drawings, in which:

FIGS. 1 to 5 are semidiagrammatic, transverse sectional views, withcertain components in elevation, illustrating successive steps of oneembodiment of a method of connecting a service line to a main inaccordance with the invention;

FIG. 6 is an elevationalview of a main having partially completedservice connections thereon;

ICC

FIG. 7 is a transverse sectional View taken along the arrowed line 7-7of FIG. 6;

FIGS. 8 to 10 are semidiagrammatic, transverse sectional views, withcertain components in elevation, which are similar to FIG. 7, but whichillustrate successive steps or" another embodiment of the method of theinvention for completing the partially completed service line connectionshown in FIG. 7;

FIG. l1 is an enlarged sectional View taken along the arrowed line 1l-llof FIG. 10; l

FIG. 12 is a View similar to PIG. 10, but illustrating still anothermethod of making a service line connection in accordance with theinvention;

FIG. 13 lis an enlarged sectional View taken along the arrowed line13-13 of FIG. 12; and

FIG. 14 is a view similar to'FlG. 9, but illustrating yet anotherapparatus and method of making a service line connection inV accordancewith the invention.

Referring first to FIGS. l to 5 of the drawings, the numeral 2i)designates a main, such as an underground gas main, water main, or thelike, to which a service line 22 isto be connected. The steps requiredto connect the service line 22 to the main Ztl will now be consideredsequentially.

Initially, a suitable tool 24 is attached to the main 20, as by means ofa clamp 26. The tool 24 provides a space 28 which is isolated from theatmosphere and one end or side of which is bounded by the main 263. Moreparticularly, the tool 24 provides an annular packing means 39, shown asa simple O-ring for convenience, which engages the main Ztl on one sidethereof to form one end of the isolated space 28. The other end of theisolated space 28 is formed either by a closure means 32, or by anannular packing means 34, shown as a simple O-ring for convenience,engageable with components to be described. The closure means 32 isshown, for purposes of illustration, as comprising simply a gate valve36 engageable with a valve seat 3S.

The next step is to insert into the tool 24 a combined drilling andtapping means 4i) having a shank l2 engageable with the annular packingmeans 3d in a duid-y tight manner to form the outer end of the isolatedspace 28. Under these conditions, the gate valve 36 is out of engagementwith its seat 3S. The shank 42 of the drilling and tapping means 46terminates in a stem 44 which projects from the outer end of the tool 24through a feed screw 46 engageable with an annular shoulder 47 on thedrilling and tapping means. As will be clear from FIG. 1 of thedrawings, by simultaneously rotating the drilling and tapping means 40and the feed Vscrew 46, a hole i8 is drilled in the main 2) and issubsequently tapped. The drilling and tapping means d@ and the feedscrew 46 may be rotated in any suitable manner, as by applying wrenches,not shown, to t-he outer ends 5t) and S2 of the stern da and the feedscrew 416, respectively. `Once the hole 48 is drilled and tapped, itestablishes Huid communication between the main 20 and the inner end ofthe isolated space 2S. The isolated space 28 is provided adjacent itsinner end with a well 29 which receives cuttings produced by thecombined drilling and tapping means 40 so that such cuttings areprevented from entering the closure means 32 and the packing means 34 todamage same.

Next, as shown in FIG. 2 of the drawings, the drilling and tapping means40 is partially Withdrawn from the isolated space 2S, whereupon the gatevalve 36 is re-engaged with the valve seat 3S to close the outer end ofthe isolated space toV prevent the loss of uid from the main 2l). Next,the drilling and tapping means 40 is com-,

pletely withdrawn from the tool 24 by completely unscrewing the feedscrew 46.

Then, as shown in FIG. 3 of the drawings, a nipple 5d Patented Sept.,24, i963.

is inserted into the tool 24 and into Huid-tight engagement with thepacking means 34, whereupon the gate valve 35 may be disengaged from itsseat 38 to permit threading of the inner end of the nipple into thetapped hole 4S. The nipple 54 is provided at its outer end with areduced-diameter stem 56 providing an annular shoulder S7 correspondingto the annular shoulder 47 on the drilling and tapping means 40 andengageable by the feed screw 46. As will be apparent, the feed screw 46may' be rotated to advance the nipple 54 until the inner end thereofengages the main 2d, whereupon the nipple may be rotated to thread theinner end thereof into the tapped hole 43. Since the feed screw 46 isutilized to guide both the drilling and tapping means 4i? and the nipple54, the inner end of the nipple is brought into accurate register withthe tapped' hole 45.

The nipple 54 is provided at or adjacent its outer end with a fusibleplug 58 of `a metal, or metal alloy, having a relatively low meltingpoint. The fusible plug 5S must be capable of withstanding the pressurein the main 2t? and in many instances this may be achieved merely bypressing the plug into the nipple 54. In the event that very high mainpressures must be sustained, the interior of the nipple 54 may beroughened, grooved, or the like, and the plug 5S cast in place so thatit is keyed to die nipple.

After the nipple 54 has been threaded into the tapped hole 48, the tool24 is detached from the main Ztl, thereby arriving at the conditionshown in FIG. 4 of the drawings. Under these conditions, the fusibleplug 5S prevents loss of fluid from the main 20 while the service line22 is being connected thereto, as will now 'be described.

Referring to FlG. 5 of the drawings, thev next step is to slip theservice line 22 over the nipple 54, whereupon the inner end of theservice line may ybe welded -to the main 29, as indicated at 6i). Thenecessary hookup of the service line Z2 is then completed. For example,the Iservice line 22 may be connected to `a `gas meter associated with aresidence.

Finally, after completing the entire service line installation, thefusible plug 58 is melted out, as by playing the ame of a torch 62 onthe service line 22 opposite the fusible plug. ri`he heat generated inthis fashion melts the surface of the fusible plug 58, whereupon thepressure in the main 2t? blows the plug out of the nipple 54. Theresulting remnant of the fusible plug 58 remains in the service line 22and is small enough that it produces no significant obstruction.

The melting temperature of the 'fusible plug 58 and the length of thenipple 54 are such that the heat generated in welding the service line22 to the main 26 does not heat the nipple at the plug suticiently toloosen the plug. For example, assuming that the main 2G, the serviceline 22 and the nipple S4 are all made of ordinary pipe, it has beenfound that, with a nipple length of approximately eight inches, the plugtemperature reaches only about 220 F. during 4the course of Welding theservice line 22 to the main 2h. Thus, making the fusible plug 53 out ofa metal or metal alloythat melts at 275 F. provides an Iample margin ofsafety.

yWhile the nipple 54 is shown as smaller than and spaced radiallyinwardly from the service line 22, ythis is not `absolutely essential,although Ithe radial spacing does reduce transmission of the weldingheat to the fusible plug 5S, which is desirable. Also, the nipple 54has, as a lmatter of convenience, .been shown somewhat longer,

in relation to its diameter, than would be the case in actual practice.Further, in actual practice, the shoulder 57 engageable by the feedscrew 46 lis preferably closer to the outer end of the nipple 54, i.e.,closer to the end thereof containing the fusible plug 58.

It will be noted from the foregoing that the present invention providesa very simple method of connecting the service line 22 to the main 20and one which can be made rapidly with simple and inexpensivecomponents,

s thereby minimizing the cost of making the connection. Further, sincethe service line is welded to the main 2) there are no exposed threadedconnections so that corrosion problems are minimized. Further, with thesimple structure of the connection which the invention provides,

it may be protected `against corrosion readily, may be wrapped readily,or the like. Still another .advantage is that there is no necessity ofinitially providing the main 20 with fittings which can corrode, belbroken olf, or the like, prior to use.

Turning now to FIGS. 6 to ll'of the drawings, the

embodiment of the invention illustrated therein employsk the same basicconcepts as that hereinbefore described, but utilizes somewhat differentcomponents and somewhat different steps.

Referring first to FIG. 7 of the drawings, the rst step with thisembodiment is to weld a nipple 70 to a main 1 v 72. The nipple '70, inthis instance, ultimately forms a part of the service line. j' The nextstep is to slip over the nipple 72 a tool 74 which is similar to thetool 24 and cor-responding com'- ponents of which are identified by thesame vreference y numerals. The tool 74 differs from the tool 24 inthat, instead of being seated against the main '72, it is seated againstthe outer end of the nipple '70 and is provided with an annular packingmeans 76, shown as a simple Oring, engageable with the exterior of thenipple 7G and sealing the inner end of the isolated space 28. The toolvThe drill SG is similar to the drilling and tapping means 4) andidentical reference numerals are employed to p designate correspondingcomponents.

Elaborating on the foregoing paragraph, the drillt) is inserted into thetool 74 until the shank 42 thereof engages the packing means 54 in afluid-tight manner.

Thereupon, the valve 36 is disengaged from its seat 38 and, by means ofthe feed screw 46, the drill S0 is brought a Subsequently, bysimultaneously rotating the drill and the feed screwV into engagementwith the main 72.

46, a hole 82 is drilled in the main 72 at the inner end of the nipple7i). Subsequently, the drill 80 is withdrawn,

the gate valve 36 being seated prior to disengaging the shank 42 of thedrill from the packing means 34.

Referring to FIG. 9, the next step is to insert a plug means S4 throughthe tool 74 into the nipple 7). This insertion is effected with a rod 86which carries the plug means 84, the rod 86 first engaging the packingmeans 34 in a fluid-tight manner, whereupon the gate valve V36 may beunseated to permit insertion of the plug means 84 into the nipple '70.The feed screw 46 may act on the rod 86 during the course of insertingthe plug means 84 in the same manner that it acts on the drill 80, therod 86 being rovided with an .annular shoulder, not shown, correspondingto the annular shoulder 47. Subsequently, the rod 86 is withdrawn fromthe nipple 7? and the tool 74, and the tool is then detachedA The plugmeans 84 includes a collar 88' carrying a fusi-ble plug 90 in the formof a disc set in an internal Y annular groove in Ithe collar. The collar88 carries externally thereof an O-ring 92 which makes a fluid-tightseal with the interior wall of the nipple 70. The collar 33 is held inplace within the nipple '70 against the pressure Ywithin the main 72 bya Washer 94 against whichthe outer end of the collar 88 is seated andwhich is provided with prongs 96 adapted to bite into the interior wallof the nipple 70. Such a washer `94 is capable of holding the pluggedcollar 88 in place against substantial main pressures.

'Phe next step is to weld a service line 98 to the outer end of thenipple 70, the nipple in this instance forming a part of the serviceline. service line 9S is completed.

rFhe nal step is to heat the nipple 70 opposite the plug means S4suiciently to melt out the fusible plug 90 in the same manner as thefusi-ble plug 53, lthe collar 88 and the washer 94 remaining within thenipple 70.

As in the case of the embodiment yof FIGS. 1 to 5 of the drawings, thelocation of the plug means 84 relative Ato the weld between the nipple7) and the service line 98 and the melting temperature of the-fusibleplug 90 are such that the heat generated in welding the service line 98to -the nipple 70 will not melt out the fusible plug 90. Also, thefusible plug 90 may -be protected from the welding heat at theconnection between the service line 98 and the nipple 7 il by making thecollar 88 of a heat insulating material. Doing this, however, requiresthe application of more heat to the plug means 34 in the course ofmeltin out the plug 99.

Referring to FIGS. 12 and 13 of the drawings, illustrated therein is aservice connection to a main 110 comprising a nipple 112 and a serviceline 114, communication between the main 110 and the nipple 112 beingestablished through a hole 116 in the main. In this case, the main 110,the nipple 112 and the service line 114 are all formed of suitableplastic materials bon-ded together by Then, the hookup of thecementin-g, heat sealing, or the like, instead of by welding.

To provide stronger connections, the nipple I112 terminates at its innerend in a saddle 118 complementary to the main 110, and, for the samereason, la telescoping connection 121) is provided between the nipple112 :and the service line 114.

In making the service connection of FIGS. 12 and 13, the nipple 112 isfirst bonded to the main 110. The hole 116 is then drilled insubstantially the same manner as and with substantially the sameequipment las the hole 82 in the main 72. Then, a fusible plug 122 isinserted into the nipple 112 in substantially the same manner as andwith substantially the same equipment as the plug means S4. The fusibleplug 122 is preferably snapped into an annular groove 124; in the nipple112, the plastic material of which the nipple is formed beingsuiiciently flexible to permit this. The fusible plug 122 is providedthereon with -a central boss 126 receivable in a hole in a rod, notshown, similar to the rod 86 Ifor inserting the plug means 84. The boss126 thus serves as -a means vfor connecting the fusible plug 122 to sucha rod during the insertion process.

Next, the service line 114 is bonded to the nipple 112 at thetelescoping connection 120, either by cementing, heat sealing, or -thelike.

After the service line 114 has been completely hooked up, the fusi-bleplug 122 is melted out by applying heat to the nipple 112 opposite thefusible plug. In this instance, the fusible plug 122 may be made of ametal or metal alloy having a -rather low melting point so that it canbe melted out without overheating the plastic nipple 112. Preferably,Woods met-al is used since, under such circumstances, the fusible plug122 can be melted out merely by pouring hot Water over `the nipple 112opposite the fusible plug. However, it will -be understood that thefusible plug 122 maybe melted out in other ways.

Referring to FIG. 14 of the drawings, illustrated therein is -analternative method of establishing communication between the nipple 7dand the main 72 and of preventing the escape of fluid from the mainuntil the service line 9S is connected to the outer end of the nipple.Instead of drilling the hole @2 of FIGS. 8 to l() in lthe main 72, asomewhat smaller hole 130 is drilled and tapped therein through the useof a tool 132 -similar to the tool 74 and through the use of a drillingand tapping means, not shown, similar to the drilling and tapping meansy411. In this case, the tool 132 is anchored in place by set screws 134engageable with the nipple 70, instead of by a mainencircling clamp.

After the hole 131i has -been -drilled and tapped `and the drilling andtapping means withdrawn from the tool 13.2, a plug means in the form of=a second nipple .136 is inserted into 'the nipple 7 il and is threadedinto the tapped hole 130. The nipple 136 is provided at its outer endwith a noncircular, preferably hexagonal, socket 13S adapted to receivea complementary plug 140 on the inner en-d of an inserting tool 142capable of engaging an annular packing means of the tool 132corresponding to the annular packing means 34. The nipple 136 isinserted and threaded into the tapped hole with the inser-ting tool`141-2 in much the same manner as the plug means 84 is inserted with theinserting tool or rod y86.

The nipple 136 is provided therein with a fusible plug 144 which isretained therein in much the same manner as the fusible plug 58 isretained in the nipple 54.

-After a service line, not shown, Ihas been -welded to the outer end ofthe nipple 70, and after the hookup of the service line has 'beencompleted, the nipple 70' is heated opposite the -f-usible plug 144 inthe inner nipple 136 to release the fusible plug, thereby establishingcommunication between the main 72 and the service line.

The embodiments of the invention illustrated -in FIGS. 6 to 11, in FIGS.12 land 13, and in FIG. 14 have substantially the same advantages as theembodiment illustrated in FIGS. 1 to 5 so that a further description isunnecessary.

Although exemplary embodiments of the invention have been disclosedherein `for purposes of illustration, it will be understood that variouschanges, modifications and substitutions may be incorporated in suchembodiments without departing from the spirit of the invention as denedby the claims which follow.

I claim:

1. A method of connecting a weldable service line to a Awelclable mainintermediate the ends thereof, including the steps of:

(a) welding an inner end of .a weldable nipple directly to theperipheral wall of said main with said nipple projecting laterally `fromsaid main;

(b) isolating a space which is axially aligned with said nipple randwhich communicates at an inner end thereof with the outer end ccf saidnipple;

(c) inserting a drill axially into said space through the outer endthereof and `axially into said nipple through the outer end thereof,while simultaneously maintaining the isolation of said space;

(d) drilling a hole through said peripheral wall of said main with saiddrill from the exterior of said space, -whereby to connect said main andthe innen end of said nipple in fluid communication;

(e) withdrawing said drill axially from said nipple and said spiacewhile simultaneously maintaining the isolation of said space;

'(9) inserting a plug having a fusible portion axially into said spacethrough the `outer end thereof land axially into said nipple through theouter end thereof, while simultaneously maintaining the isolati-on ofsaid space;

(g) securing said plug within said nipple :adjacent the inner endthereof from the exterior of said space;

(h) ideisolating said space;

(i) welding an end of said service line directly to the outer end ofsaid nipple; and

(j) heating said plug through said nipple suiciently to melt saidfusible portion thereof, whereby to conneet said service line in fluidcommunication with said mainthrough said nipple.

2. A method of connecting `a Weldable service line to a weldablemainintermediate the ends thereof, Iincluding the steps of:

(a) welding an inner end of a weldable nipple directly to the peripheralwall of said main with said nipple projecting laterally from said main;

(b) isolating a spiace which is axially aligned with said nipple andwhich communicates :at an inner end thereof with the outer end of saidnipple;

(Ac) inserting a hole-fonming member axially into said space through theouter end thereof `and axiallyinto said nipple through the outer endthereof, fwhile simultaneously maintaining the isolation of `said spaee;

(d) forming Ia hole through said peripheral Wall of said main with saidhole-forming member from the exterior of said space, whereby yto connectsaid main -and the inner end of said nipple in iluid communication; Y

(e) withdrawing said hole-forming member axially from said nipple andsaid space while simultaneously maintaining the isolation of said spaee;

(f) inserting 1a plug having a fusible portion axially into said spiacethrough the outer end thereof Iand laxially into said nipple through theouter end fthereof, while simultaneously maintaining the isolation ofsaid space;

(g) securing said plug within sai-d nipple fadjafcent lthe inner endthereof from the exterior of said space;

' 8 (h) deisolating said-space; L welding an end of saidserviee linedirectly to the louter end of said nipple; and

(j) heating said plug through said nipple suliciently mo lrneltt said.fusi-ble portion thereof, whereby to con` neet said servi-ee line inuid .communication with Y, Y

said main through saidnipple.

vReferenees Cited in the le of this patent UNITEDl STATES PATENTS

1. A METHOD OF CONNECTING A WELDABLE SERVICE LINE TO A WELDABLE MAININTERMEDIATE THE ENDS THEREOF, INCLUDING THE STEPS OF: (A) WELDING ANINNER END OF A WELDABLE NIPPLE DIRECTLY TO THE PERIPHERAL WALL OF SAIDMAIN WITH SAID NIPPLE PROJECTING LATERALLY FROM SAID MAIN; (B) ISOLATINGA SPACE WHICH IS AXIALLY ALIGNED WITH SAID NIPPLE AND WHICH COMMUNICATESAT AN INNER END THEREOF WITH THE OUTER END OF SAID NIPPLE; (C) INSERTINGA DRILL AXIALLY INTO SAID SPACE THROUGH THE OUTER END THEREOF ANDAXIALLY INTO SAID SPACE THROUGH THE THE OUTER END THEREOF, WHILESIMULTANEOUSLY MAINTAINING THE ISOLATION OF SAID SPACE; (D) DRILLING AHOLE THROUGH SAID PERIPHERAL WALL OF SAID MAIN WITH SAID DRILL FROM THEEXTERIOR OF SAID SPACE, WHEREBY TO CONNECT SAID MAIN AND THE INNER ENDOF SAID NIPPLE IN FLUID COMMUNICATION; (E) WITHDRAWING SAID DRILLAXIALLY FROM SAID NIPPLE AND SAID SPACE WHILE SIMULTANEOUSLY MAINTAININGTHE ISOLATION OF SAID SPACE; (F) INSERTING A PLUG HAVING A FUSIBLEPORTION AXIALLY INTO SAID SPACE THROUGH THE OUTER END THEREOF ANDAXIALLY INTO SAID NIPPLE THROUGH THE OUTER END THEREOF, WHILESIMULTANEOUSLY MAINTAINING THE ISOLATION OF SAID SPACE; (G) SECURINGSAID PLUG WITHIN SAID NIPPLE ADJACENT THE INNER END THEREOF FROM THEEXTERIOR OF SAID SPACE; (H) DEISOLATING SAID SPACE; (I) WELDING AN ENDOF SAID SERVICE LINE DIRECTLY TO THE OUTER END OF SAID NIPPLE; AND (J)HEATING SAID PLUG THROUGH SAID NIPPLE SUFFICIENTLY TO MELT SAID FUSIBLEPORTION THEREOF, WHEREBY TO CONNECT SAID SERVICE LINE IN FLUIDCOMMUNICATION WITH SAID MAIN THROUGH SAID NIPPLE.